Exposure to house dust mites is closely connected with allergic diseases such as atopic dermatitis, allergic rhinitis, and asthma. House dust mites (Dermatophagoides farinae and D. pteronyssinus) act as allergens even after their death. Therefore, repelling the house dust mites is more effective method than killing them. Many chemical agents have been used in killing house dust mite. However, it is usually reported that these chemical agents (acaricides) exhibit adverse effects and toxicity toward animals and human. For these reasons, we carried out the experiments for measuring the repellent activity of Mate tea and Jasmine tea against house dust mites in this experiment. In order to determine the concentration having the most effective repellent effect of Mate and Jasmine tea, house dust mites (D. farinae and D. pteronyssinus) were exposed at different concentrations (0, 0.015625, 0.03125, 0.0625, 0.125, 0.25, 0.5 mg/40 μL) of Mate tea and Jasmine tea extracts, respectively, for different hours (0.5, 1, 2, 3 hours). The most effective repellent effect (%) against house dust mite in 0.25 mg/40 μL of Mate tea for 2 hours was 73.5%, Jasmine Petal tea in 0.0625 mg/40 μL for 1 hour was 84.1% and Pearl Jasmine tea in 0.125 mg/40 μL for 0.5 hour was 82.8%. These results suggest that Mate tea and Jasmine tea extracts have potential effect to repel the house dust mites (D. farinae and D. pteronyssinus)

The American house dust mite, Dermatophagoides farinae Hughes, 1961 (Acari: Pyroglyphidae), is recognized as an important source of allergens in the domestic environment. An assessment was made of the toxicity of constituents from essential oil of cade, Juniperus oxycedrus L. (Cupressaceae), and related compounds as well as four experimental spray formulations containing the oil (10–40 g/liter sprays) to adult D. farinae. In a contact + fumigant mortality bioassay, methyleugenol (24-h LC50,5.82 μg/cm2) and guaiacol (8.24 μg/cm2) were the most toxic constituents to the mites and the toxicity of these constituents and benzyl benzoate did not differ significantly.

The essential oils of three Coriandrum sativum seeds cultivated from India, Russia and America were evaluated for acaricidal toxicities against Dermatophagoides farinae, D. pteronyssinus, and Tyrophagus putrescentiae. The oils of three C. sativum seeds were analyzed by gas chromatography. The oil of C. sativum seeds cultivated from India included substantially linalool (66.8%) and camphor (6.46%). In the fumigant bioassay, based on the LD50 values against D. farinae, D. pteronyssinus, and T. putrescentiae, the oil of C. sativum seeds cultivated from America (LD50, 2.62, 2.74, and 2.88 μg/cm3) was about 3.75, 3.32, and 4.17 times more active higher than benzyl benzoate (9.85, 9.10 and, 12.01 μg/cm3). The acaricidal activity of the oil of C. sativum seeds cultivated from India was 2.27, 2.03, and 2.64 times higher than that of the benzyl benzoate, followed by Russia oil. These results suggest that the oils of three C. sativum seeds might be used as suitable acaricides.

The toxicity of bay leaf (Pimenta racemosa) and palmorasa (Cymbopogon martini) essential oils, and its constituents, and structurally related compounds to adult American house dust mites, Dermatophagoides farinae was examined. Both bay leaf (24 h LC50, 131.95 μg/cm2) and palmorosa (24 h LC50, 116.10 μg/cm2) essential oils were toxic to mites. The most active principles were determined to be citral, methyleugenol, eugenol, and geranyl acetate from both bay leaf and palmorosa oils. Citral (24 h LC50, 1.13 μg/cm2), methyl eugenol (5.78 μg/cm2), eugenol (24 h LC50, 12.52 μg/cm2) and geranyl acetate (24 h LC50, 18.79 μg/cm2) were the most toxic. The toxicity of these compounds was more toxic than that of commercially available acaricides such as, benzylbenzoate (LC50,8.41μg/cm2) and deet (37.67 μg/cm2). Potent toxicity was also observed with nerol, linalool and geraniol (LC50, 21.44–54.61 μg/cm2). These compounds were consistently more toxic in closed versus open containers, indicating that their mode of delivery was largely a result of vapour action. Both bay leaf and palmorosa oil, and their constituents shown their potentials as effective alternatives for harmful synthetic acaricides for the control of Dermatophagoides populations as fumigants in contact and therefore illustrated the need for further study of these essential oils.

An assessment was made of the toxicity of basil, Ocimum basilicum, essential oil, 11 basil oil constituents, seven structurally related compounds and another 22 previously known basil oil constituents and the control efficacy of four experimental spray formulations containing the oil (1, 2, 3 and 4% sprays) to adult American house dust mites, Dermatophagoides farinae. Results were compared with those of two conventional acaricides benzyl benzoate and N,N-diethyl-3- methylbenzamide (deet). The active principles were determined to be citral, α -terpineol and linalool. Citral (24 h LC50, 1.13 μg/cm2) and menthol (1.69 μg/cm2) were the most toxic compounds, followed by methyl eugenol (5.78 μg/cm2). The toxicity of these compounds was more toxic than that of benzylbenzoate(LC50, 8.41 μg/cm2) and deet (37.67 μg/cm2). These compounds were consistently more toxic in closed versus open containers, indicating that their mode of delivery was largely a result of vapour action. Basil applied as 3 and 4% experimental sprays provided 97 and 100% mortality against the mites respectively, whereas permethrin (cis:trans, 25:75) 2.5 g/l spray treatment resulted in 17% mortality. Reasonable mite control in indoor environments can be achieved by spray formulations containing the basil oil (3 and 4% sprays) as potential contact-action fumigants.

An assessment was made of the toxicity of hiba, Thujopsis dolabrata var. hondai, oil and 24 oil constituents and control efficacy of four experimental spray formulations containing the oil (0.5. 1, 2, and 3% sprays) to adult American house dust mite (AHDM), Dermatophagoides farinae, and copra mite (CM), Tyrophagus putrescentiae. Results were compared with those of three conventional acaricides benzyl benzoate, N,N-diethyl-3-methylbenzamide (deet), and permethrin. Based on 24 h LC50 values, (–)-thujopsene was the most toxic constituent against AHDM (9.82 μg/cm2) and CM (10.92 μg/cm2) and the toxicity of the compound was nearly identical to that of benzyl benzoate (9.33 and 10.14 μg/cm2). High toxicity was also observed with (–)-(E)-pinocarveol, carvacrol, (+)-terpinen-4-ol, β-thujaplicin, cedrol, α-terpineol, (+)-ledene, thymol, and 2,4-di-tert-butylphenol against both mite species (LC50, 11.92–19.19 and 12.49–22.97 μg/cm2). These constituents were more toxic than deet (LC50, 35.53 and 38.42 μg/cm2). Hiba applied as 2 and 3% sprays provided >95% mortality against both mite species, whereas permethrin (cis:trans, 25:75) 2.5 g/L spray treatment resulted in ca 11% mortality. Global efforts to reduce the level of highly toxic synthetic acaricides in indoor environments justify further studies on hiba oil preparations containing the constituents described as potential contact-action fumigants or lead molecules for the control of mite populations.

The toxicity of red pine needle hydrodistillate (RPN-HD), 19 RPN-HD constituents and 12 structurally related compounds and control efficacy of four experimental spray formulations containing RPN-HD (0.5. 1, 2 and 3% sprays) to adult Dermatophagoides farinae was evaluated. RPN-HD (24 h LC50,68.33 μg cm–2) was toxic. Menthol was the most toxic compound (12.69 μg cm–2) and the toxicity of this compound and benzyl benzoate did not differ significantly from each other. High toxicity was also produced by α-terpineol, bornyl acetate, geranyl acetate, thymol, linalyl acetate, terpinyl acetate, citral, linalool and camphor (18.79–36.51 μg cm–2). These compounds were more toxic than either deet or dibutyl phthalate. In vapour-phase mortality tests, these compounds were consistently more toxic in closed versus open containers, indicating that their mode of delivery was largely a result of vapour action. RPN-HD 3% experimental spray provided 95% mortality against adult D. farinae, whereas permethrin (cis:trans,25:75)2.5gL–1 spray treatment resulted in 0% mortality. In the light of global efforts to reduce the level of highly toxic synthetic acaricides in indoor environments, RPN-HD and the compounds described merit further study as potential biocides for the control of Dermatophagoides populations as fumigants with contact action.

The object of this study was the acaricidal activities of acetophenone (AP) and its derivatives for their potentials as natural acaricides using fumigant and contact toxicity bioassays against Dermatophagoides farinae, D. pteronyssinus, and Tyrophagus putrescentiae. Based on the LD50 values of AP derivatives against D. farinae, 3’-methoxyAP (0.41 ㎍/㎠) was 89.9 times more toxic than DEET (36.87 ㎍/㎠), followed by 4’-methoxyAP (0.52 ㎍/㎠), 2’-methoxyAP (0.75 ㎍/㎠), 2’-hydroxy-5’-methoxyAP (1.03 ㎍/㎠), 2’-hydroxy -4’-methoxyAP (1.29 ㎍/㎠), AP (1.48 ㎍/㎠), 2’-hydroxyAP (1.74 ㎍/㎠), 2’,5’-dimethoxyAP (1.87 ㎍/㎠), 2’,4’-dimethoxyAP (2.10 ㎍/㎠), and benzyl benzoate (9.92 ㎍/㎠). With regard to structure-activity relationships between acaricidal activity and functional groups (hydroxyl and methoxy groups) on the AP skeleton, a mono-methoxy group (2’-, 3’-, and 4’-methoxyAP) on the AP skeleton was more toxic than the other groups (2’,4’- and 2’,5’-dimethoxyAP, 2’- and 4’-hydroxyAP, 2’-hydroxy-4’-methoxyAP, 2’-hydroxy-5’-methoxyAP, and 4’-hydroxy-3’-methoxyAP). These results indicated that acaricidal activity against three mite species was changed with the introduction of functional radicals (hydroxyl and methoxy groups) onto the AP skeleton.

The American house dust mite, Dermatophagoides farinae Hughes, is the most important factor of allergic diseases, such as atopic dermatitis, rhinitis, and asthma. The protein-denaturing activity of nerolidol (1), chrysin (2), and spathulenol (3) identified in the Brazilian propolis against D. farinae was evaluated using SDS-PAGE and dot-blot immunoassay. Results were compared with those of the currently available dust mite protein-denaturing agent tannic acid. SDS-PAGE showed that application of test compounds and tannic acid (100 μg each) caused complete disappearance of D. farinae protein bands. In a dot-blot immunoassay, test compounds and tannic acid (100 μg each) strongly inhibited the IgE-binding reactivity to D. farinae protein of a highly mite-sensitive asthmatic patient. The Brazilian propolis constituents described merit further study as potential dust mite-allergen denaturants for protection from humans from various diseases caused by house dust mites.

Various acaricidal agents have been used to reduce the dust mite population. On the point of keeping people away from mite allergens, however, repelling mites from the living space of human is more effective than just killing them, because the dead bodies of mites still act as allergen. To examine the potential of Artemisia in controling house dust mites, Artemisia extract was evaluated for its repellency to Dermatophagoides farinae and D. pteronyssinus. Repellency tests were performed using filter-paper circles cut in halves. The Artemisia extract was applied on each half at concentrations of 0, 0.1, 0.2, 0.4 and 0.8㎕/㎠. Proper repellent effects of Artemisia extract on house dust mites were observed at the concentrations of ＞0.4㎕/㎠. As a positive control, lavender essential oil was used at concentrations of 0, 0.0125, 0.025, 0.05 and 0.1㎕/㎠. Lavender oil showed proper repellent effects at concentrations of ＞0.05㎕/㎠. These results suggest that Artemisia extract has potential to control the house dust mites, and might be useful as a dust mite repellent.

Dyed loess and charcoal fabrics are sold in market as bedding. They have a lot of functions so that people are getting to increase their expenditure for them. Thus we investigated a repellent effect of loess fabrics and charcoal fabrics against house dust mites. The evaluation of the repellent effect of dyed loess fabrics and charcoal fabrics was conducted by using Dermatophagoides farinae and D. pteronyssinus. We compared the repellent effect of dyed loess fabrics at different doses of 0.3, 1.0, 3.2, 10.0 ㎎/㎠ and dyed charcoal fabrics at different doses of 0.3, 0.6, 1.0 ㎎/㎠. Commercial loess fabrics did not have a repellent effect against house dust mites. but commercial charcoal fabrics had the repellent effect by 78% against them. In case of dyed charcoal fabrics added with charcoal powder over 0.6 ㎎/㎠, they showed the repellent effect by over 80%. These results suggest that loess fabrics and charcoal fabrics have a repellent effect of against house dust mites and they can be commercially used for the purpose.

The acricidal potency of some essential oils can be applied to the control of house dust mites. But it is more effective keeping the house dust mites away than killing them because they remain as allergens even after death. The most efficient repellent concentration of lavender and tea tree in 10㎕ against house dust mites (Dermatophagoides farinae and D. pteronyssinus) were experimented by direct contact bioassay method at various doses ; 2.5, 1.25, 0.625, and 0.3125% and at vairous exposure times ; 15, 30, 60, 120, and 180 minutes. The most effective dose of essential oils (lavender and tea tree) against house dust were 0.625% and the repellent effectiveness at the mowt effective dose of 0.625% were 95.6% for lavander and 96.2% for tea tree, respectively. These results suggest that lavender and tee tree can be effectively used in the control of house dust mites.

The insecticidal potency of some essential oils have been suggested that they may find an application in the control of house dust mites. We compared the repellent effect of four essential oils ; lemon grass (Cymbopogon nardus), lavender(Lavandula vera), rosemary(Rosmarinus officinalis) and ylang ylang(Cananga odorata). The oils were exposed at different doses(0.1, 0.05, 0.025, 0.0125, and 0.00652 ㎕/㎠) and different times(1, 2, 3, 4, 5 hours) on house dust mites(Dermatophagoides farinae and D. pteronyssinus). The repellent effects(%) of essential oils that were exposed at 0.1 ㎕/㎠ and for 1 hours against house dust mites were lemon grass(63.3%) and rosemary(61%), lavender(40%), ylang ylang(40%) in the order named.